A 168-line MATLAB code for topology optimization with the adaptive bubble method (ABM)

This paper presents a MATLAB code implementation of the Adaptive Bubble Method (ABM) published by Cai and Zhang (2020) for topology optimization. The ABM has the main feature of inserting deformable holes adaptively into the design domain to reflect the designer's motto that "The art of structure is where to put the holes. " This method consists of three modules: (i). implicit description of holes with the closed B-spline (CBS) curve possessing high deformability; (ii). determination of optimal insertion points in each iteration using the topological derivative combined with a matrix operation-based searching scheme; (iii). fixed grid-based finite element analysis (FEA) using the ersatz material model. Representative numerical examples are tested to illustrate the implementation of the ABM. A compact 168-line MATLAB code is provided in the Appendix and explained in detail for educational purpose.